pressure DODGE NEON 2000 Service User Guide

CAUTION: Seal must not be dimpled, stretched, or
out±of±shape in any way. If seal is NOT shaped cor-
rectly, equalize pressure in seal and shape it by
hand.
(8) Position outer C/V joint sealing boot into its
retaining groove on outer C/V joint housing. Install
sealing boot to outer C/V joint retaining clamp evenly
on sealing boot.
(9) Clamp sealing boot onto outer C/V joint hous-
ing using Crimper, Special Tool C-4975-A and the fol-
lowing procedure. Place crimping tool C-4975-A over
bridge of clamp (Fig. 44). Tighten nut on crimping
tool C-4975-A until jaws on tool are closed completely
together, face to face (Fig. 45).
(10) Install the driveshaft requiring boot replace-
ment back on the vehicle. See Driveshaft Removal
and Installation in this section for the required drive-
shaft installation procedure.
Fig. 43 Sealing Boot Retaining Clamp Installed
1 ± CLAMP
2 ± JAWS OF SPECIAL TOOL C-4975A MUST BE CLOSED
COMPLETELY TOGETHER HERE
3 ± INTERCONNECTING SHAFT
4 ± SEALING BOOTFig. 44 Crimping Tool Installed on Sealing Boot
Clamp
1 ± CLAMP
2 ± TRIPOD JOINT HOUSING
3 ± SPECIAL TOOL C-4975A
4 ± SEALING BOOT
Fig. 45 Sealing Boot Retaining Clamp Installed
1 ± CLAMP
2 ± TRIPOD HOUSING
3 ± SPECIAL TOOL C-4975A
4 ± JAWS OF SPECIAL TOOL C-4975A MUST BE CLOSED
COMPLETELY TOGETHER HERE
5 ± SEALING BOOT
3 - 16 DIFFERENTIAL AND DRIVELINEPL
DISASSEMBLY AND ASSEMBLY (Continued)

DESCRIPTION AND OPERATION
BASE BRAKE SYSTEM OPERATION
When a vehicle needs to be stopped, the driver
applies the brake pedal. The brake pedal pushes the
input rod of the power brake booster into the booster.
The booster uses vacuum to ease pedal effort as force
is transferred through the booster to the master cyl-
inder. The booster's output rod pushes in the master
cylinder's primary and secondary pistons applying
hydraulic pressure through the chassis brake tubes
and proportioning valves (rear only) to the brakes at
each tire and wheel assembly.
Front disc brakes control the braking of the front
wheels; rear braking is controlled by rear drum
brakes as standard equipment. Rear disc brakes and
an antilock brake system (ABS) with traction control
are optional.
The hydraulic brake system is diagonally split on
both the non-antilock and antilock braking systems.
This means the left front and right rear brakes are
on one hydraulic circuit and the right front and left
rear are on the other.
Vehicles equipped with the optional antilock brake
system (ABS) use a system designated Mark 20e.
This system shares most base brake hardware used
on vehicles without ABS. A vehicle equipped with
ABS, however, uses a different master cylinder and
brake tubes. Also included in the ABS system is an
integrated control unit (ICU) and four wheel speed
sensors. These components are described in detail in
the ANTILOCK BRAKE SYSTEM section in this
group of the service manual. All vehicles with ABS
come standard with four-wheel-disc brakes and trac-
tion control.
The parking brakes are hand-operated. When
applied, the parking brake lever pulls on cables that
actuate brake shoes at each rear wheel. The parking
brake lever has an automatic adjusting feature that
takes up any excessive slack in the parking brake
cable system.
BASE BRAKE SYSTEM COMPONENTS
BRAKE PEDAL
A suspended-type brake pedal is used on this vehi-
cle. The pedal pivots on a shaft mounted in the pedal
support bracket under the instrument panel. The
pedal connects to the power brake booster input rod
and pushes it in when the pedal is applied.
The brake pedal and it's pad are serviceable sepa-
rately.
POWER BRAKE BOOSTER
There are two different power brake booster
designs, although externally they appear the same.
All vehicles use a 205 mm tandem diaphragm power
brake booster. The two boosters are internally tuned
differently depending on whether the vehicle is
equipped with the standard front disc/rear drum
brake combination or the optional front disc/rear disc
(four-wheel disc) brake combination. If the power
brake booster requires replacement, be sure it is
replaced with the correct part.
The power brake booster can be identified by the
tag attached to the body of the booster assembly (Fig.
1). This tag contains the following information: The
production part number of the power brake booster,
the date it was built and who manufactured it.
The power brake booster reduces the amount of
force required by the driver to obtain the necessary
hydraulic pressure to stop the vehicle.
The power brake booster is vacuum-operated. The
vacuum is supplied from the intake manifold on the
engine through the power brake booster check valve
(Fig. 2).
As the brake pedal is depressed, the power booster
input rod moves forward. This opens and closes
valves in the power brake booster, allowing atmo-
spheric pressure to enter on one side of a diaphragm.
Engine vacuum is always present on the other side.
This difference in pressure forces the output rod of
the power booster out against the primary piston of
the master cylinder. As the pistons in the master cyl-
inder move forward, hydraulic pressure is created in
the brake system.
Fig. 1 Master Cylinder and Power Brake Booster
1 ± POWER BRAKE BOOSTER PARTS IDENTIFICATION TAG
2 ± POWER BRAKE BOOSTER
3 ± BRAKE FLUID PRESSURE SWITCH
4 ± MASTER CYLINDER
5 - 2 BRAKESPL

The power brake vacuum booster assembly mounts
on the engine side of the dash panel. The booster
input push rod connects to the brake pedal. A vac-
uum line connects the power booster to the intake
manifold. The master cylinder is bolted to the front
of the power brake booster.
MASTER CYLINDER
The base brakes on a vehicle not equipped with
ABS use a standard compensating port master cylin-
der, while vehicles equipped with ABS use a center
valve design master cylinder. The information pro-
vided here applies only to the non-ABS master cylin-
der. For information on the master cylinder used on
vehicles with ABS, refer to the ANTILOCK BRAKE
SYSTEM section in this service manual group.
The non-ABS master cylinder is a four-outlet
design with two screw-in proportioning valves. One is
attached directly to the inboard side of the master
cylinder housing while the other is attached to the
bottom (Fig. 3). Vehicles equipped with rear drum
brakes use a master cylinder with a 22.23 mm (0.875
in.) bore diameter, while vehicles equipped with rear
disc brakes use a 23.82 mm (0.937 in.) bore diameter
master cylinder.
The master cylinder body is an anodized aluminum
casting. It has a machined bore to accept the master
cylinder piston and also has threaded ports with
seats for hydraulic brake line connections.
The master cylinder's primary outlet ports supply
hydraulic pressure to the right front and left rearbrakes while the secondary outlet ports supply
hydraulic pressure to the left front and right rear
brakes (Fig. 3).
BRAKE FLUID RESERVOIR
The master cylinder has the brake fluid reservoir
mounted on top of it which gravity feeds brake fluid
to the master cylinder when it is required. The res-
ervoir is made of see-through plastic and it houses
the brake fluid level switch.
BRAKE FLUID LEVEL SWITCH
The brake fluid level switch is located in the brake
fluid reservoir on the master cylinder (Fig. 1). It
senses the level of the brake fluid within the reser-
voir and when the level drops below an acceptable
level, the switch closes and completes the ground cir-
cuit for the red BRAKE warning lamp. This turns on
the red BRAKE warning lamp. For additional infor-
mation, refer to RED BRAKE WARNING LAMP also
in this section.
PROPORTIONING VALVE
NOTE: Only vehicles without antilock brakes have
proportioning valves. Vehicles with antilock brakes
have electronic brake distribution that is built into
the integrated control unit.
Fig. 2 Power Brake Booster
1 ± MOUNTING STUD
2 ± PARTS IDENTIFICATION TAG
3 ± MASTER CYLINDER MOUNTING STUDS
4 ± VACUUM CHECK VALVE
Fig. 3 Non-ABS Master Cylinder
1 ± RIGHT FRONT BRAKE TUBE
2 ± LEFT FRONT BRAKE TUBE
3 ± LEFT REAR BRAKE TUBE
4 ± REAR PROPORTIONING VALVES
5 ± RIGHT REAR BRAKE TUBE
PLBRAKES 5 - 3
DESCRIPTION AND OPERATION (Continued)

Proportioning valves balance front to rear braking
by controlling the brake fluid hydraulic pressure to
the rear brakes. Under light pedal application, the
proportioning valve allows normal fluid flow to the
rear brakes. Under higher pedal effort, the valve
reduces fluid pressure to the rear brakes.
The non-antilock master cylinder is a four-outlet
design with two screw-in proportioning valves
attached directly to the master cylinder housing (Fig.
3). One proportioning valve controls each rear brake.
BRAKE TUBES AND HOSES
The purpose of the brake tubes and flex hoses is to
transfer the pressurized brake fluid developed by the
master cylinder to the brakes at each wheel of the
vehicle. The flex hoses connect the chassis brake
tubes, which are mounted to the vehicle's underbody,
to the brake at each wheel, allowing for movement of
the vehicle's suspension. The brake tubes are steel
with a corrosion-resistant nylon coating applied to
the external surfaces. The flex hoses are made of
reinforced rubber.
DISC BRAKES (FRONT)
The front disc brakes consist of the following com-
ponents (Fig. 4):
²Brake caliper - single-piston, floating type
²Brake shoes and linings
²Brake rotorWhen the brakes are applied, fluid pressure is sent
to each brake caliper. The pressure at the caliper is
exerted equally against the caliper piston. The pres-
sure applied to the piston is transmitted directly to
the inboard brake shoe. This forces the shoe lining
against the inner surface of the brake rotor. At the
same time, fluid pressure within the caliper piston
bore forces the caliper to slide inward on its guide
pins. This action brings the outboard shoe lining into
contact with the outer surface of the brake rotor.
This pressure on both sides of the brake rotor causes
friction, bringing the vehicle to a stop.
BRAKE CALIPER
The caliper is a one-piece casting with the inboard
side containing a single piston cylinder bore (Fig. 5).
The front disc brake caliper piston, is manufac-
tured from a phenolic compound. The outside diame-
ter of the caliper piston is 54 mm.
A square-cut rubber piston seal is located in a
machined groove in the caliper cylinder bore. This
provides a hydraulic seal between the piston and the
cylinder wall (Fig. 6). The piston seal is designed to
pull the piston back into the bore of the caliper when
the brake pedal is released. This maintains the
proper brake shoe-to-rotor clearance.
A rubber dust boot is installed in the cylinder bore
opening and in a groove in the piston (Fig. 6). This
prevents contamination in the bore area.
The caliper is mounted to the steering knuckle
using bushings, sleeves and two guide pin bolts (Fig.
5). The guide pin bolts thread directly into bosses on
the steering knuckle.
Two machined abutments on the steering knuckle
position the caliper. The guide pin bolts, sleeves, and
bushings control the side-to-side movement of the
caliper. All of the front brake force generated during
braking of the vehicle is taken up directly by the
steering knuckles of the vehicle.
BRAKE SHOES AND LININGS
There are two brake shoes mounted to each caliper,
one inboard and one outboard (Fig. 5). When brake
shoes are replaced, only brake shoes meeting the
original equipment manufacturer (OEM) formulation
(such as Mopartreplacement parts) should be used.
As front disc brake shoe linings wear, master cyl-
inder reservoir brake fluid level will drop. Fluid level
should be checked after replacing shoes.
Front disc brakes are equipped with an audible
wear indicator on the outboard brake pad (Fig. 5).
This sensor emits a sound when the brake lining
may need inspection or replacement.
Fig. 4 Front Disc Brakes
1 ± STEERING KNUCKLE
2 ± BRAKE PADS AND LININGS
3 ± BRAKE ROTOR
4 ± DRIVING HUB
5 ± CALIPER ASSEMBLY
5 - 4 BRAKESPL
DESCRIPTION AND OPERATION (Continued)

BRAKE ROTOR
The brake shoe linings contact the brake rotor.
Each front brake rotor is vented to help cool it during
and after brake applications. It is mounted on the
studs of the front wheel bearing hub.
DRUM BRAKES (REAR)
Rear drum brakes are standard equipment on this
vehicle. The rear drum brakes consist of the major
components listed in the figure (Fig. 7). Other com-
ponents related to the brake shoes themselves can be
seen in the next figure (Fig. 8).
The rear wheel drum brakes are a two-shoe, inter-
nal-expanding type with an automatic adjuster screw
(Fig. 8). The automatic adjuster screw is actuated
each time the brakes are applied. The automatic
adjuster screw is located directly below the rear
brake wheel cylinder.
Fig. 5 Front Disc Brake Caliper
1 ± CALIPER GUIDE PIN BOLT
2 ± SLEEVE
3 ± BUSHING
4 ± CALIPER
5 ± PISTON SEAL
6 ± PISTON
7 ± DUST SEAL
8 ± WEAR INDICATOR
9 ± ANTI-RATTLE CLIP10 ± BRAKE SHOE
11 ± BRAKE SHOE
12 ± ANTI-RATTLE CLIP
13 ± BUSHING
14 ± SLEEVE
15 ± CALIPER GUIDE PIN BOLT
16 ± CAP
17 ± BLEEDER SCREW
Fig. 6 Piston Seal Function
1 ± PISTON
2 ± CYLINDER BORE
3 ± PISTON SEAL BRAKE PRESSURE OFF
4 ± CALIPER HOUSING
5 ± DUST BOOT
6 ± PISTON SEAL BRAKE PRESSURE ON
PLBRAKES 5 - 5
DESCRIPTION AND OPERATION (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
PEDAL PULSATES/SURGES
DURING BRAKING1. Rear brake drum out of round or
disc brake rotor has excessive
thickness variation.1. Isolate condition as rear or front.
Reface or replace brake drums or rotors
as necessary.
PEDAL IS SPONGY 1. Air in brake lines. 1. Bleed brakes.
2. Power brake booster runout
(vacuum assist).2. Check booster vacuum hose and
engine tune for adequate vacuum supply.
Refer to power brake booster in the
diagnosis and testing section.
PREMATURE REAR WHEEL
LOCKUP1. Contaminated brake shoe linings. 1. Inspect and clean, or replace shoes.
Repair source of contamination.
2. Inoperative proportioning valve
(non-ABS vehicles only).2. Test proportioning valves folowing
procedure listed in diagnosis and testing
section. Replace valves as necessary.
3. ABS EBD not functioning. 3. Refer to the ABS section and Chassis
Diagnostic Procedures manual.
4. Improper power brake booster
assist.4. Refer to power brake booster in the
diagnosis and testing section.
STOP LAMPS STAY ON 1. Brake lamp switch out of
adjustment.1. Adjust brake lamp switch.
2. Brake pedal binding. 2. Inspect and replace as necessary.
3. Obstruction in pedal linkage. 3. Remove obstruction.
4. Power Brake Booster not allowing
pedal to return completely.4. Replace power brake booster.
VEHICLE PULLS TO RIGHT
OR LEFT ON BRAKING1. Frozen brake caliper piston. 1. Replace frozen piston or caliper. Bleed
brakes.
2. Contaminated brake shoe lining. 2. Inspect and clean, or replace shoes.
Repair source of contamination.
3. Pinched brake lines. 3. Replace pinched line.
4. Leaking piston seal. 4. Replace piston seal or brake caliper.
5. Suspension problem. 5. Refer to the Suspension group.
PARKING BRAKE -
EXCESSIVE HANDLE
TRAVEL1. Rear brakes out of adjustment. 1. Adjust rear drum brake shoes, or rear
parking brake shoes on vehicles with rear
disc brakes.
POWER BRAKE BOOSTER
BASIC TEST
(1) With engine off, depress and release the brake
pedal several times to purge all vacuum from the
power brake booster.
(2) Depress and hold the pedal with light effort (15
to 25 lbs. pressure), then start the engine.
The pedal should fall slightly, then hold. Less effort
should be needed to apply the pedal at this time. If
the pedal fell as indicated, perform the VACUUM
LEAK TEST listed after the BASIC TEST. If thepedal did not fall, continue on with this BASIC
TEST.
(3) Disconnect the vacuum hose on the side of the
vacuum check valve that leads to the speed control,
then connect a vacuum gauge to the open vacuum
port on the valve.
(4) Start the engine.
(5) When the engine is at warm operating temper-
ature, allow it to idle and check the vacuum at the
gauge.
PLBRAKES 5 - 11
DIAGNOSIS AND TESTING (Continued)

If the vacuum supply is 12 inches Hg (40.5 kPa) or
more, the power brake booster is defective and must
be replaced. If the vacuum supply is below 12 inches,
continue on with this BASIC TEST.
(6) Shut off the engine.
(7) Connect the vacuum gauge to the vacuum ref-
erence port on the engine intake manifold.
(8)
Start the engine and observe the vacuum gauge.
If the vacuum is still low, check the engine tune
and repair as necessary. If the vacuum is above 12
inches, the hose or check to the booster has a restric-
tion or leak.
Once an adequate vacuum supply is obtained,
repeat the BASIC TEST.
VACUUM LEAK TEST
(1) Disconnect the vacuum hose on the side of the
power brake booster vacuum check valve that leads
to the speed control, then connect a vacuum gauge to
the open vacuum port on the valve.
(2) Remove the remaining hose on the vacuum
check valve that is not the vacuum supply hose com-
ing from the intake manifold. Cap off the open port
on the check valve.
(3) Start the engine.
(4) Allow the engine to warm up to normal operat-
ing temperature and engine idle.
(5) Using vacuum line pliers, close off the vacuum
supply hose near the booster and observe the vacuum
gauge.
If the vacuum drop exceeds 1.0 inch Hg (3.3 kPa)
in one minute, repeat the above steps to confirm the
reading. The vacuum loss should be less than 1.0
inch Hg in one minute time span. If the loss is more
than 1.0 inch Hg, replace the power brake booster. If
it is not, continue on with this test.
(6) Remove the pliers from the hose temporarily.
(7) Apply light effort (approximately 15 lbs. of
force) to the brake pedal and hold the pedal steady.
Do not move the pedal once the pressure is applied
or the test results may vary.
(8) Have an assistant reattach the pliers to the
vacuum supply hose.
(9) Allow 5 seconds for stabilization, then observe
the vacuum gauge.
If the vacuum drop exceeds 3.0 inches Hg (10 kPa)
in 15 seconds, repeat the above steps to confirm the
reading. The vacuum loss should be less than 3.0
inches Hg in 15 seconds time span. If the loss is
more than 3.0 inches Hg, replace the power brake
booster. If it is not, the booster is not defective.
DRUM BRAKE AUTOMATIC ADJUSTER
To properly test the drum brake automatic
adjuster, the aide of a helper inside the vehicle to
apply the brakes will be necessary.(1) Raise the vehicle. Refer to HOISTING in the
LUBRICATION AND MAINTENANCE group for the
proper lifting procedure.
(2) Remove the access plug from the rear adjust-
ment slot in each brake support plate.
(3) Insert a thin screwdriver in the adjustment
slot and push back the adjustment lever. With the
lever in this position, back the star wheel adjustment
off approximately 10 notches. This will eliminate the
possibility that the brake is at full adjustment, and
can be adjusted no further.
(4)
Remove the screwdriver from the adjustment slot.
(5) Watch the star wheel through the adjustment
slot, while a helper applies the brake pedal. As the
brake shoes apply, the adjustment lever should move
downward, turning the star wheel. A definite rotation
of the adjuster star wheel can be observed if the
automatic adjuster is working properly.
If the star wheel does not move as indicated, the
brake drum needs to be removed and further inspec-
tion of the rear brakes is necessary.
(6) If the star wheel is operating properly, readjust
the brakes. Refer to ADJUSTMENTS in this section
of this service manual group.
(7) Reinstall the adjustment slot access plug.
(8) Lower the vehicle.
BRAKE ROTOR
Any servicing of the rotor requires extreme care to
maintain the rotor within service tolerances to
ensure proper brake action.
Excessive runout or wobble in a rotor can increase
pedal travel due to piston knock-back. This increases
guide pin sleeve wear due to the tendency of the cal-
iper to follow the rotor wobble.
When diagnosing a brake noise or pulsation, the
machined disc braking surface should be checked and
inspected.
BRAKING SURFACE INSPECTION
Light braking surface scoring and wear is accept-
able. If heavy scoring or warping is evident, the rotor
must be refaced or replaced. Refer to SERVICE PRO-
CEDURES in this section of this group for informa-
tion on brake rotor machining.
Excessive wear and scoring of the rotor can cause
improper lining contact on the rotor's braking sur-
face. If the ridges on the rotor are not removed before
new brake shoes are installed, improper wear of the
shoes will result.
If a vehicle has not been driven for a period of
time, the rotor's braking surface will rust in the
areas not covered by the brake shoes at that time.
Once the vehicle is driven, noise and chatter from
the disc brakes can result when the brakes are
applied.
5 - 12 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

The in-line proportioning valves used on this vehi-
cle require special pressure fittings to test the pro-
portioning valves for proper proportioning valve
function. The pressure fittings are installed before
and after the proportioning valve being tested to ver-
ify proportioning valve is maintaining the required
hydraulic pressure to the rear wheel brake which it
controls.
The testing of proportioning valves for this vehicle,
if equipped with ABS, can be found in the
ANTILOCK BRAKE SYSTEM section.
PROPORTIONING VALVE TEST
The test procedure is the same for either rear pro-
portioning valve. After road testing the vehicle to
determine which wheel skids first, follow the proce-
dure below for testing the suspect proportioning
valve.
(1) Using a brake pedal holding tool as shown (Fig.
22), depress the brake pedal past its first one inch of
travel and hold it in this position. This will isolate
the master cylinder from the brake hydraulic system
and will not allow the brake fluid to drain out of the
master cylinder reservoir.
(2) Use the figure shown to determine which pro-
portioning valve needs to be tested (Fig. 21).
(3) Remove the hydraulic brake tube from the pro-
portioning valve controlling the rear wheel of the
vehicle that has premature wheel skid.
(4) Remove the proportioning valve from its outlet
port on the master cylinder.CAUTION: Be sure the pressure test fittings being
installed into master cylinder and proportioning
valve, have the correct thread sizes needed.
(5) Install the Brake Pressure Adapters, Special
Tool 8644 and 6805-3 onto the proportioning valve
(Fig. 23).
(6) Install the proportioning valve (with tools) back
into the outlet port on the master cylinder.
(7) Attach a Pressure Gauge, Special Tool
C-4007-A, to each pressure adapter (Fig. 24).
(8) Remove the brake pedal holding tool. Bleed any
air out of the pressure gauge hoses at the pressure
gauge.
(9) With the aid of a helper, apply pressure to the
brake pedal until the reading on proportioning valve
inlet gauge is at the target inlet pressure shown in
the BRAKE PROPORTIONING VALVE APPLICA-
TIONS AND PRESSURE SPECIFICATIONS table
Fig. 22 Brake Pedal Holding Tool
1 ± CLUTCH PEDAL (IF EQUIPPED WITH MANUAL TRANSAXLE)
2 ± THROTTLE PEDAL
3 ± BRAKE PEDAL HOLDING TOOL
4 ± STEERING WHEEL
5 ± DRIVER'S SEAT
6 ± BRAKE PEDAL
Fig. 23 Tools On Valve
1 ± PROPORTIONING VALVE
Fig. 24 Pressure Gauge Set
1 ± SPECIAL TOOL C-4007±A
5 - 16 BRAKESPL
DIAGNOSIS AND TESTING (Continued)

following this procedure. If the inlet gauge pressure
overshoots its target pressure when the pedal is
depressed, release the brake pedal, relieving the
pressure in the system, before reapplying the pedal
to reach the target pressure at the inlet gauge. This
is necessary to get an accurate reading of the outlet
pressure.
(10) Once inlet pressure has been achieved, check
the pressure reading on the proportioning valve out-
let gauge. If the proportioning valve outlet pressure
does not agree with value shown in the table, replace
the proportioning valve. If proportioning valve is
within pressure specifications, the valve is good and
does not require replacement.(11)Reinstall the brake holding tool on the brake
pedal and remove the test equipment from the vehicle.
(12) Remove the tools from the proportioning
valve.
(13) Install the proportioning valve in the master
cylinder and hand tighten until the proportioning
valve is fully installed and its O-ring seal is seated
into the master cylinder. Torque the proportioning
valve to 40 N´m (30 ft. lbs.).
(14) Install the brake tube on the proportioning
valve. Torque the tube nut to 17 N´m (145 in. lbs.).
(15) Bleed the affected brake line. See BASE
BRAKE BLEEDING in this section of this service
manual group.
BRAKE PROPORTIONING VALVE APPLICATIONS AND PRESSURE SPECIFICATIONS
Sales
CodeBrake System Type Split Point Slope IdentificationInlet
PressureOutlet Pressure
BRA 14º Disc/Drum 300 psi 0.34 Black Band 1000 psi 550-650 psi
BRD 14º Disc/Disc 400 psi 0.43 Bar Code Band 1000 psi 600-700 psi
BRAKE FLUID CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts. Swelling indicates the
presence of petroleum in the brake fluid.
To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If the fluid sep-
arates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If the brake fluid is contaminated, drain and thor-
oughly flush the brake system. Replace all the rubber
parts or components containing rubber coming into
contact with the brake fluid including: the master
cylinder; proportioning valves; caliper seals; wheel
cylinder seals; ABS hydraulic control unit; and all
hydraulic fluid hoses.
SERVICE PROCEDURES
BRAKE FLUID LEVEL CHECKING
Brake fluid level should be checked a minimum of
twice a year.
Master cylinder reservoirs are marked, FULL and
MIN, indicating the allowable brake fluid level range
in the master cylinder brake fluid reservoir (Fig. 25).
CAUTION: Use only MoparTbrake fluid or an equiv-
alent from a tightly sealed container. Brake fluid
must conform to DOT 3 specifications. Do not use
petroleum-based fluid because seal damage in the
brake system will result.Although there is a range, the preferred level is
FULL. If necessary, adjust the brake fluid level to
the FULL mark on the side of the master cylinder
brake fluid reservoir.
BASE BRAKE BLEEDING
NOTE: For bleeding the ABS hydraulic system,
refer to ANTILOCK BRAKE SYSTEM BLEEDING in
the ANTILOCK BRAKE SYSTEM section of this ser-
vice manual group.
Fig. 25 Master Cylinder
1 ± POWER BRAKE BOOSTER PARTS IDENTIFICATION TAG
2 ± POWER BRAKE BOOSTER
3 ± BRAKE FLUID PRESSURE SWITCH
4 ± MASTER CYLINDER
PLBRAKES 5 - 17
DIAGNOSIS AND TESTING (Continued)

CAUTION: Before removing the master cylinder
cap, wipe it clean to prevent dirt and other foreign
matter from dropping into the master cylinder res-
ervoir.
CAUTION: Use only MoparTbrake fluid or an equiv-
alent from a fresh, tightly sealed container. Brake
fluid must conform to DOT 3 specifications.
Do not pump the brake pedal at any time while
having a bleeder screw open during the bleeding pro-
cess. This will only increase the amount of air in the
system and make additional bleeding necessary.
Do not allow the master cylinder reservoir to run
out of brake fluid while bleeding the system. An
empty reservoir will allow additional air into the
brake system. Check the fluid level frequently and
add fluid as needed.
The following wheel circuit sequence for bleeding
the brake hydraulic system should be used to ensure
adequate removal of all trapped air from the hydrau-
lic system.
²Left rear wheel
²Right front wheel
²Right rear wheel
²Left front wheel
MANUAL BLEEDING
NOTE: To bleed the brakes manually, the aid of a
helper will be required.
(1) Attach a clear plastic hose to the bleeder screw
and feed the hose into a clear jar containing enough
fresh brake fluid to submerge the end of the hose
(Fig. 26).
(2) Have a helper pump the brake pedal three or
four times and hold it in the down position.
(3) With the pedal in the down position, open the
bleeder screw at least 1 full turn.
(4) Once the brake pedal has dropped, close the
bleeder screw. After the bleeder screw is closed,
release the brake pedal.
(5) Repeat the above steps until all trapped air is
removed from that wheel circuit (usually four or five
times).
(6) Bleed the remaining wheel circuits in the same
manner until all air is removed from the brake sys-
tem. Monitor the fluid level in the master cylinder
reservoir to make sure it does not go dry.
(7) Check the brake pedal travel. If pedal travel is
excessive or has not been improved, some air may
still be trapped in the system. Rebleed the brakes as
necessary.
(8) Test drive the vehicle to verify the brakes are
operating properly and pedal feel is correct.
PRESSURE BLEEDING
NOTE: Follow pressure bleeder manufacturer's
instructions for use of pressure bleeding equip-
ment.
Following the same wheel circuit sequence as pre-
scribed for manual bleeding.
(1) Attach Adapter, Special Tool 6921, to the mas-
ter cylinder reservoir (Fig. 27).
Fig. 26 Proper Method for Purging Air From Brake
System (Typical)
1 ± CLEAR HOSE
2 ± BRAKE CALIPER
3 ± BLEEDER SCREW
4 ± CLEAN BRAKE FLUID
Fig. 27 Special Tool 6921
1 ± MASTER CYLINDER
5 - 18 BRAKESPL
SERVICE PROCEDURES (Continued)